


Back Again

by hoomhum



Category: Sherlock (TV)
Genre: Fluff, Gen, Hurt/Comfort, John does his best to deal with that, Sherlock is a literal child, small amounts of angst
Language: English
Status: In-Progress
Published: 2017-10-02
Updated: 2017-10-02
Packaged: 2019-01-08 08:22:53
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,754
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12250620
Author URL: https://archiveofourown.org/users/hoomhum/pseuds/hoomhum
Summary: John Watson wakes up one day to find that his flatmate has been turned into a five year old. Nothing could have prepared him for this.





	Back Again

**Author's Note:**

> This has been in my simmering folder for literally years and I may have posted something like it somewhere else, but I figured I'd share it here with you all.

John woke to the sound of chaos coming from the sitting room. That in itself wasn’t unusual. What _was_ unusual was that on this particular morning that chaos came in the form of a crying child. Possibly this was an experiment of Sherlock’s to determine the affect of a child in distress on an ex-military doctor.

For twenty seconds, John debated whether going down and telling Sherlock off would confirm the man’s hypothesis or disprove it. A second after that the crying increased in decibel and John couldn’t take it any more. He pulled on his dressing gown and stormed downstairs.

“Sherlock, this is bloody ridi-“

He stopped midsentence, because the sight that greeted him was not his flatmate sitting at the desk with his laptop and a notebook to record John’s reactions, but a small child in an oversized t-shirt sitting on the floor and clutching his scraped knee.

Before he had time to fully comprehend the scene, the boy was clinging to his legs, sobbing muffled in John’s pyjama pants. All of his questions died in his throat as he crouched down to comfort the little one.

“Let’s have a look at that,” he said, pulling the child up and balancing him on his hip. The scrape had already started to clot over, but it was worth disinfecting. Not to mention there was little else he could do; Sherlock was no where in sight. When he did show his face again, though, he and John would be having a long conversation about kidnap and the irresponsibility of leaving a child—no more than five, by his guess—unattended, especially in their flat.

The kitchen was no more of a disaster area than usual, which was to say that Sherlock’s experiments had taken over the table and most of the counter space. John moved a pile of dishes into the sink and plopped the child down on the freshly cleared space.

Pale blue eyes, still wet from crying tracked his movements as he ducked down under the sink to fetch their first aid kit.

“This is going to sting a bit,” he warned the child as he opened an alcohol swab. “But-“

“Is gonna kill the bacteria so I don’ get infected.”

“That’s right,” John said, quickly cleaning the area. The little one screwed up his face, but didn’t react past a loud sniffle. John dug around the case, looking for a plaster of an appropriate size.

“Do you have dinosaur ones?”

“Erm—sorry?”

“Dinosaur ones. Stegosaurus is my favourite.” The kid spoke with a slight lisp and there were still tear stains on his face, but he looked hopeful.

“Only plain ones, sorry.”

“My says coloured ones are for little kids, but he’s boring.” Folding his arms against his chest, the kid’s face crumpled a bit when John applied the plain coloured plaster.

“My?” John asked, absently, as he packed away the kit. Now that the imminent crisis was taken care of, he needed to find Sherlock and demand to know what the hell was going on.

“My bruver, Mycroft. Do you know where he is? Mum’ll be mad if he lost me.”

 

John wasn’t even given five minutes to acclimate to the idea that the floppy haired limpet of a child was his flatmate before the world seemed to fall apart. The scariest part, once he had accepted the inevitable, was that Sherlock didn’t know who he was aside from a kind stranger that had helped him when he was injured. The real Sherlock, the properly aged one, was nowhere to be found.

Shortly after he had been cleaned up, the miniature Sherlock inquired, “Will you take me home now?”

John balked. This _was_ home.

“I—I can’t right now. Do you remember how you got here?”

The child shook his head and John sighed. He helped the little one down from the counter and pulled out a tin of biscuits and a plate.

“Come sit in here and have a few of these. I’ll phone your family,” he promised, leading Sherlock to the sitting room. There was suspicion in his flatmate’s eyes, but he settled easily enough on the settee and John hurried back into the kitchen to dial Mycroft.

The elder Holmes did not answer his phone, nor did his assistant. The number rang and rang, each ring growing increasingly ominous. John tried Sherlock’s phone next, just in case, and found it ringing in the man’s bedroom.

“Scuse me, Mr John?” Sherlock peeked around the corner of the doorframe. “I—I wanna go home now. Have you called mummy?”

“I couldn’t get ahold of her,” John said apologetically, trying to keep the panic out of his voice. “You should stay here for now.”

“Mum gave me ‘mergency money for the bus, if I get lost. I think I’m gonna…”

“No, you can’t leave.” The statement came out more sharply than John intended and Sherlock’s lower lip trembled, fear in his eyes.

“I don’t know you,” he said, little fist clenched around a five pound note. “C-can I phone the police?”

The police! Why hadn’t John thought of that? He pulled out his phone and knelt down, dialling Lestrade’s number.

“You’re right, that’s probably a good idea. They’ll figure this out,” he said, and Sherlock offered him a small, unsure smile as John pressed the button to put the phone on speaker.

“Detective Inspector Lestrade,” came a slightly tinny voice. Sherlock obviously recognized the words detective and inspector and he crept nearer, putting a hand on John’s knee to steady himself as he leaned over the phone.

“Hullo? Can you come get me?” He said into the phone. John let him speak, unsure what to say himself. “I’m scared an’ I’ve lost my bruver.”

“John?” Lestrade asked, confusion in his voice. “Who is this?”

“Lestrade, there’s been a… situation. Can you come to 221b?”

There was a beat of silence. “Yeah, alright. Should I inform child services?”

“Just come, please. It’s easier to explain in person.”

 

Sherlock looked a bit more at ease after they had called Lestrade. Little features furrowed in concentration, he smoothed out his emergency money (lord only knew where he had found it), folded it carefully, and moved as though to tuck it into a pocket. He realized hallway through the motion that he was wearing an overly large t-shirt. He frowned.

“Where’s my clothes?” He plopped down on the lino, tugging the shirt over his knees and down to his ankles, wrapping his arms tightly around himself. He looked thoroughly miserable and distressed. “I’m not dressed proper.”

John ducked into the sitting room, pulling the throw from the back of his chair. He dropped to his knees beside the child and wrapped him carefully in the knitted material.

“It’s okay not to be dressed if you’ve got a proper blanket to wrap up in. Is that better?”

Sherlock ducked down, tugging the throw up over his head and snuggling into it. Soon only his nose and a few curls peeked out.

“’S nice.”

John was saved responding by the ringing of his phone. Mycroft had finally deigned to phone back.

“What can I do for you, John?” Despite the wording, he sounded annoyed. His voice was barely recognizable through the static. Wherever he was, he didn’t have a very good connection.

“Your brother’s a five year old.”

“I haven’t the time for his childish behaviour. You’ll have to deal with him yourself.”

There was a click as the elder Holmes hung up. John sighed, exasperated. He surreptitiously snapped a picture of the curly haired boy wrapped up in the throw and sent it. Not twenty seconds later, John’s phone pinged with a message from Mycroft’s assistant.

_He’s coming to Baker St as soon as possible. Expect him around five_.

Right, John thought, looking at the text. Apparently he was out of the country. At least he was coming.

 

By the time Lestrade arrived, John had successfully coerced Mrs Hudson into doing some shopping for his unexpected guest and had divided his efforts between tidying the flat of anything that posed an immediate harm to a child and entertaining Sherlock.

Currently the boy was lying on his stomach in the sitting room with a pencil in his hand and a stack of A4 in front of him. He was as focused on his drawing as John had ever seen him with his experiments, a fact which John found incredibly endearing.

“You’re not going to believe this,” John told Lestrade when he opened the door. “I almost don’t believe it.”

“What’re you on about?”

“Come on up.”

John lead the way upstairs and stepped into the sitting room. Sherlock hadn’t moved, tiny tongue caught between his teeth as he concentrated on the paper in front of him.

“Sherlock? Detective Inspector Lestrade is here.”

Pale blue eyes looked up at once and Sherlock got his feet under him, clutching the throw around his shoulders. He approached Lestrade cautiously, as the man just barely managed to conceal a gape. Lestrade froze for a moment, before looking to John.

“Found him when I woke up this morning,” John said. Lestrade nodded.

“Sherlock,” he said carefully, kneeling down to put himself on the child’s level. “Do you know who I am?”

“I phoned you,” Sherlock responded. He hunched his shoulders, bringing the blanket up to his ears. “Mr John fixed my knee, but I don’t know where my bruver is. I just wanna go home.”

Near the end of his speech, tears began to well up in the little one’s eyes. He scrubbed at his nose with a blanket covered hand and took a wobbly step toward John. Hoping that some part of his flatmate’s mind recognized him as a trustworthy friend, John knelt down and offered Sherlock his hand. The little boy ran into him with such force that it knocked him the rest of the way to the floor and he cuddled the bundle of blanket and tears into his lap, muttering condolences.

When Sherlock’s tears subsided into occasional sniffles, Lestrade gathered himself together and spoke in a calmly authoritative voice.

“Right now you’re going to stay with John while I sort things out, alright? I’ll talk to your family, but it’ll be safer for you to stay with the doctor for now.”

“Am I sick?” Sherlock asked, voice muffled in John’s jumper. John and Lestrade exchanged looks. How were they to explain the concept of de-aging to a five year old?

“Not… not quite. You’re special and I need to keep an eye on you for a bit,” John said finally.

“Oh,” Sherlock said, shoulders hunching defensively. “Sorry.”

That reaction struck John as incredibly wrong. He tried to get Sherlock to look at him, but the little boy refused to meet his gaze, tucking his chin to his chest and effectively zoning out. He didn’t speak another word.

“You called his brother?” Lestrade asked quietly over Sherlock’s head. John nodded.

“He’ll be here this evening. I don’t understand how this could have happened.”

“No idea, mate. It could still be some kind of bloody ruse on Sherlock’s part but… that’s starting to seem pretty unlikely.”

“It’s him,” John said with confidence. “You should’ve seen him earlier. There’s no way he found some kid who could fake all of that.”

The bundle of blankets in his lap, apparently having grown bored of their conversation, wriggled free and Sherlock went back to his drawing. John stood, feeling completely out of his depth. He’d dealt with a few children through the course of his work, but never for more than half an hour and none of them were Sherlock. The little boy seemed calm enough now, but there was no telling what kind of damage he might do when he grew bored.

“Cup of tea?” he offered Lestrade. The DI shook his head apologetically.

“I’ve got to get back to the Yard. Looking after consulting detectives that have turned into children isn’t what I’m paid for.”

“Right,” John cringed. “Of course.”

“Good luck with him, though. Let me know how it gets sorted.”

Once Lestrade had gone, John phoned to say he’d be missing his shift at the clinic. He picked up the novel he had been reading the previous evening, sank into his chair and, with Sherlock decisively in his line of sight, settled in to wait.

 

Mrs Hudson returned before Mycroft arrived. She was burdened with a terrifying half dozen shopping bags, which she left in the kitchen before bustling into the sitting room.

“Ooh, Sherlock dear,” she said, scooping the startled little boy up into her arms blanket and all. “I’ve picked up some things for you and John. Would you like to see?”

Sherlock pulled the blanket up to his nose, exhibiting a shyness John rarely saw in him as an adult. He nodded his head cautiously. Mrs Hudson planted a kiss on top of his curls and swept back into the kitchen. Curious, John followed.

“I know you boys never have any food in, so I picked up some basics,” she said, depositing Sherlock in a chair and beginning to unpack bread, jam, apples, biscuits, juice and a number of other ‘necessities’ like chocolates and popsicles.

“I’ve got him a few outfits and a pair of sneakers,” she continued, moving on to the next bag. “And a jacket since it’s so nippy out. There are pyjamas and a few toys so he doesn’t get too bored while you sort this out.”

She plucked a floppy eared stuffed bunny from one bag and offered it to Sherlock. The little boy hesitated.

“For me?” he asked in a small, disbelieving voice. His surprise made John’s chest tight.

“Of course, dear,” Mrs Hudson told him, tucking the bunny into the folds of Sherlock’s blanket. He grabbed for it immediately, pulling the toy into his makeshift cocoon. “And I picked up some plastic tumblers and utensils, John.”

“You’re a life-saver, Mrs Hudson. You really are.” He pecked her cheek before turning to Sherlock. “What do you say to Mrs Hudson for buying all of this?”

“Thank you Missus Hudson,” Sherlock said, clutching his bunny and pressing his face into its soft body.

“You should put him down for a nap before he keels over, dear,” Mrs Hudson said, patting the boy’s head. “The pyjamas are right here.”

John couldn’t help smiling fondly as Sherlock climbed down from the chair. He fetched the pyjamas and cut off the tags before leading Sherlock into his room.

“Can you manage on your own?”

Sherlock gave him a look that suggested yes he could and had been able to dress himself for quite some time, thank you. The resemblance to his older self was uncanny.

“Alright then. Give me a shout if you need anything. I’ll be right in the other room.

When no reply was forthcoming, John retreated to the kitchen. He slumped in the chair that Sherlock had recently abandoned and put his head in his hands. Sherlock was a child. A _child._

“I’ll make you a cuppa dear,” Mrs Hudson said, patting his shoulder consolingly. “Just this once.”

“How are you so calm about this?” John asked, working to keep the panic from his voice. Mrs Hudson hummed as she put on the kettle.

“He’s always doing mad things,” she said. “He’s Sherlock. That’s just his way.”

“He’s never turned himself into a child before,” John pointed out, exhaling heavily. “You don’t think it’s permanent, do you?”

“I haven’t the faintest. But it’s no good worrying about that now. You’ll manage.”

John was quiet for a moment, thoughtful as Mrs Hudson passed him a mug. She puttered about the kitchen, tidying.

“Does he seem… subdued… to you? I figured he’d be wild as a child, but I guess I was wrong.”

Mrs Hudson didn’t reply for a moment, and when she did she clucked her tongue worriedly. “I don’t know, dear, I really don’t. He’s never said a word about his childhood to me.”

“Nor me,” John agreed. Sherlock never spoke about his earlier years, except in reference to his brother. Even then it was never positive.

Eventually, Mrs Hudson headed back downstairs. She patted John’s shoulder again and left him to his thoughts.

 

When Sherlock woke from his nap his curls were a right mess. They were the first things John saw as well, which had him stifling his laughter as the little boy approached. The urge to giggle faded though, once he caught sight of the child's expression.

"What's the matter?" he asked, setting his book aside at once. Sherlock avoided his gaze, glancing around the sitting room instead. He found the paper and pencil which Mrs Hudson had tidied up onto the coffee table and knelt down to continue to draw. Concerned, John moved to the sofa. "It's alright, Sherlock. You can trust me."

Sherlock peered up shyly from beneath his curls. "My says not to trust strangers. Is he gonna come get me soon? I'll miss my lessons and then mum will be angry."

"Your lessons?"

"Violin, John," a voice said from the doorway. Mycroft was standing there, leaning against the door frame. His ever present umbrella tapped absently at the floor as he focused upon his younger-- much, much younger now-- brother. "Mrs Holmes started him at a young age."

"Apparently," John said, frowning. These references to mummy getting angry were a bit worrisome. A kid at this age ought to be running around and playing. He hadn't started clarinet until he was a teen, but then again, the Holmes’ seemed to be a different breed entirely.

"Don't look so disdainful, John," Mycroft said, interrupting his thoughts. "She taught him herself."

John didn't bother to reply. Instead he looked to Sherlock, who had set down his pencil and edged closer to John, so that he was nearly leaning against his knee. He stared openly at Mycroft, as though assessing him. His mouth remained firmly closed and one hand curled around the hem of his rocket ship pyjama shirt.

"Do you know who I am, Sherlock?" Mycroft asked, stepping forward. His voice was a touch gentler than it had been when he spoke to John, but it held no affection. Sherlock shook his head, sucking his bottom lip into his mouth.

"I'm your mother's brother. Your brother was named after me, in fact." John did a double take at this new information, but then relaxed, realizing that obviously Mycroft couldn't introduce himself as Sherlock's brother. "You've met me a couple of times before, but I'm not surprised you don't remember. You were very young."

"I always remember," Sherlock muttered. He'd left his bunny in the bedroom and seemed to find John's knee an acceptable replacement to hide his face behind.

"Of course you do," Mycroft allowed, nodding. "Your mother's been called away on a trip to France, so I'm afraid you'll be staying with Doctor Watson here for a while."

"Where's my bruver?"

"School, of course. He won't be home on holiday for another few weeks. Do you understand?"

Sherlock bobbed his head, peering back up at Mycroft for a second before turning away. He crawled onto the sofa and pulled his knees up, leaning against John.

"Mr John is nice. He hasn't got any dinosaur plasters, though."

A flicker of fondness passed over Mycroft's face before he schooled it away. His gaze returned to John.

"May I have a word in private, John?"

John gave in to the temptation to ruffle Sherlock's hair as he stood. "Right. Be back in a mo."

He lead Mycroft into the kitchen and set about making tea out of sheer habit.

"What are the facts, John," Mycroft demanded, as soon as they were alone. "How did this happen?"

"Dunno. Last night he was his usual self and this morning I came down to find a kid in the sitting room, crying over a scraped knee."

Mycroft's gave swept the room, taking in the half-finished experiments, stacks of dishes, and clutter that covered nearly every surface. He was clearly agitated, mouth pulled into a frown. John couldn't blame him, exactly, but the way the man was acting seemed almost as though this entire incident was John's fault.

"Look, I--"

"Is this yesterday's post?" Mycroft asked suddenly, pointing to a pile of letters on one counter with his umbrella. John shrugged.

"Suppose so. Why, what is it?" He moved toward the pile, ready to sort through them for whatever it was the elder Holmes had identified, but was stopped by a firm hand on his shoulder. Mycroft pulled on a pair of thin leather gloves and picked up the first envelope, running his fingers along the underside of the flap.

"Just as I suspected." He held out his hand, showing John a fine dusting of white powder. Before John could ask, he located a spare evidence bag and dropped the envelope inside along with the gloves. "See the return address? It's just a name, S. Moran."

"Okay," John said, still not quite following. "But what does that mean? You know how this happened?"

"There is a facility under my control responsible for a variety of scientific achievements, the latest of which has been focused on the rehabilitation of the wicked."

"By turning them into children?"

"Obviously, there's more to it than that." Mycroft tutted, tucking the evidence bag into the pocket of his jacket. "In any case, it appears someone has gone against orders and taken matters into their own hands."

"This Moran fellow, then?"

"You misunderstand me. Someone decided to turn Jim Moriarty into a child," Mycroft said, as though this explained everything. It did not.

"What about Sherlock?"

"It would appear that this Moran fellow has decided to share with you the joy of caring for a consulting genius. Don't be concerned. My people will begin work to create the compound to reverse the change immediately. I can’t imagine it will take any longer than a few weeks.” Mycroft turned toward the door.

“That’s it, then? No threats to take him away, have him raised by some of your creepy doctors?” John asked, feeling a little indignant that Mycroft didn’t seem to care much that his brother was suddenly five years old.

“I’m far too busy to deal with him at the moment,” Mycroft replied. “In any case, he trusts you and you are competent enough to handle him. As it stands I have a scientist to eviscerate.”

John did not envy the scientist in question. A crash came from the sitting room and he was not sure he envied himself much either.

“I’ll leave you to it, then,” Mycroft told him, and then swept from the room just as the wails started up.

 

The wailing continued right up until John crossed the threshold of the sitting room. At that point Sherlock sniffled instead, one hand clutching at the back of his curl-covered head.

"Is he gone?" he asked, from his crumpled position on the floor. "He didn't seem very nice. Not like My at all."

"Yes, he's gone." John scooped the little one up and balanced him on his hip. "How did you hit your head?"

"I wanted a book." Sherlock pointed to the shelves over John's shoulder. "Mummy says books belong in the library, but there were some in the bedroom too and that one's about plants, but I couldn't reach." As he spoke he leaned precariously away from John to grab at the bookshelf.

"I see." John shifted nearer so that Sherlock could reach. "Well, you can have whatever books you like wherever you want them while you're staying with me. I don't mind so long as you don't make too much of a mess."

The wide eyed look that Sherlock gave him made John wonder just how much self-directed play time Sherlock had been allowed as a child. Perhaps the shyness and uncertainty were a result of his brilliant mind, but John found himself worrying about the little one. He sat him down in his arm chair.

"Do you want to stay in and read or do you want to go out for a walk? We could go to the park."

"Would I hafta dress up in my going out clothes?"

John sighed. Of course the Holmes' would have fancy clothing for every occasion.

"Nope. Mrs Hudson bought you some trousers and t-shirts that should be nice and comfy. You won't have to worry about them getting dirty and, if you want, we can bring the book too in case you get bored."

No sooner had John finished speaking than had Sherlock wriggled out of his seat. He ran toward his room, excitement clear on his face. Shaking his head with laughter, John set the book safely aside and then went to help Sherlock cut off the tags and pick out his clothes for going to the park.

 

"Stay where I can see you," John said, once they had reached the playground. "I'm going to sit right here. Just give me a shout, alright?"

"Kay!" Without a backwards glance, Sherlock bounded away. He was easy to spot with his dark hair and bright blue shirt. John set the two books that Sherlock had picked out down on the bench beside him and then placed the floppy eared bunny on top of them. Sherlock had absolutely insisted when he realized that John didn't mind him bringing a toy out of the house. As John rested his hand on the books he considered where he might find a stuffed dinosaur for his young charge's amusement.

"Nice day," a voice said from over his shoulder. "Which one's yours?"

The newcomer came around the bench and sat down, giving John a small smirk. He was tall and blond, with a bit of stubble on his chin. He was a rough looking person, but apparently had a child on the playground as well.

"Oh, I'm not--" John stopped, realizing what it would sound like if he finished that sentence. "I'm looking after a friend of mine's kid. He's not mine."

At that moment, Sherlock turned to him and waved from the top of a tower. He was a bit timid in comparison with the other children running about, but he seemed to be having a nice time.

"Cute," the man said. "Curls like that ought to be a sin."

John's defences rose immediately and the man noticed, if the way he laughed was anything to go by.

"Relax, Doctor Watson. I'm not going to shoot a child in broad daylight at a park." He fished in his pocket and pulled out a cigarette and lighter. "Jim would throw a fit or play in the blood and I don't want to deal with either of those outcomes so..." He shrugged, blowing out a stream of smoke.

"Moran, I'm guessing?" John said, watching the playground from the corner of his eye. "So Jim is..."

"At the swings," Moran replied. "And that's Colonel Sebastian Moran, if you want to know. Call me Colonel."

"I'll call you whatever the hell I want," John said, hands clenching into fists. "What do you want?"

Moran laughed again, a bit bitterly. "I want someone to share my pain. I figured Sherlock ought to be just as bad. Is he a nightmare?"

John spotted a pale, skinny little boy at the swing set that couldn't possibly be anyone but the consulting criminal in question. He was twisting the chains on his swing, preparing to let them loose and spin out.

"We're having a lovely time, thanks," he said, checking that Sherlock was still doing alright. He seemed to be entertaining himself on a slide, figuring out the best position to go down in order to maintain maximum speed. "But the next time you have the urge to forward along some mad chemicals, do us a favour and _don’t_."

"Touchy," Moran said, lowering the sunglasses that were resting on top of his head. "Your temper's going to get even worse in the next few weeks, I'm sure of it. There's no reason I ought to suffer alone, Doctor. I'll be in touch."

He stood, stabbing out his cigarette and calling out to Jim. The little boy went running to him willingly enough and the two followed one of the winding park paths, Moran walking with his hands stuffed into his pockets and Jim running ahead. John looked between them and where Sherlock had just exited the slide. Two five year old geniuses in his life: he hadn't ever imagined this.


End file.
